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- ItemScanning electron microscopy study of infective juveniles Heterorhabditis bacteriophora (Nematoda: Heterorhabditidae)(Wydawnictwo UMCS, 2004-06-15) Skrzypek, Henryk; Kazimierczak, Waldemar; Kreft, AnnaStudies were conducted on the morphology of infective larvae Heterorhabditis bacteriophora using a scanning electron microscopy. The purpose of the studies was to point to the morphological and morphometric characters of infective larvae of entomogenous nematodes that are useful in taxonomy and species identification. It was found out that the studies using SEM make it possible to analyze the morphological characters unvisible in an optic microscope. Morphometric properties can also be examined in SEM, and since the measurements are very accurate they can be applied in taxonomic studies and in species identification. The preparation of the material for the studies in SEM and their performance is neither more labour-consuming nor more tiresome than in optic microscopy.
- ItemEffectiveness of infection of Cameraria ohridella (Lepidoptera: Gracillariidae) larvae by entomopathogenic nematodes Steinernema sp. and Heterorhabditis sp. (Nematoda: Rhabditida)(Wydawnictwo UMCS, 2004-06-15) Kreft, Anna; Skrzypek, Henryk; Kazimierczak, WaldemarThe purpose of the present studies was to evaluate the susceptibility of Cameraria ohridella larvae to infection by entomopathogenic nematodes Steinernema sp. and Heterorhabditis sp. in laboratory conditions. The experiments were done at the temperatures 20 ◦C and 25 ◦C with the use of three doses of the pathogen, namely 5, 25 and 50 nematodes/insect. The results showed that Cameraria ohridella larvae were susceptible to infection by entomopathogenic nematodes. Out of two strains of entomopathogenic nematodes used in the studies, the one that was more effective in infecting Cameraria ohridella at the temperature 20 ◦C was Steinernema sp., while at the temperature of 25 ◦C Heterorhabditis sp. infected the insects more intensively. Results of the experiments showed that with lower doses of invasive larvae of nematodes (5 larvae/insect, 25 larvae/insect) Steinernema sp. PIS81 was a more pathogenic strain towards Cameraria ohridella as compared to Heterorhabditis sp. PIH81.
- ItemGradual disapperance of vacuolated enterocytes in the small intestine of neonatal piglets(Kraków: Polish Physiological Society, 2007) Skrzypek, Tomasz; Valverde Piedra, Jose Luis; Skrzypek, Henryk; Kazimierczak, Waldemar; Biernat, Marzena; Zabielski, RomualdThe unique feature of enterocytes in newborn mammals is the presence of an apical canalicular system (ACS) leading to production of large vacuoles, important for colostral macromolecule uptake. The vacuolated fetal-type enterocytes (VFE) enable transfer of colostral and milk proteins from the intestinal lumen across the epithelium without loosing their biological activity. First VFE are observed in the pig and lamb fetuses in the second trimester of pregnancy, located at the upper part of villi in the proximal region of the fetal small intestine and subsequently in the middle and distal regions. After birth the VFE are replaced with enterocytes lacking ACS. The present study aimed to investigate the depletion of VFE in the small intestine in the sow reared pig neonates during the first postnatal weeks using scanning electron microscopy (SEM). The SEM analysis demonstrated the gradual disappearance of vacuolated enterocytes in time. VFE remained in the jejunum for a few days after birth, whereas in the duodenum single VFE were present only at birth. In the proximal jejunum, the VFE were localized in the upper part of the villi, and disappeared until the day 3 of life. VFE were present in the mid and distal jejunum, and diminished gradually until day 14 of life. By the day 21 of life, the vacuolated cells were not observed neither in the jejunum nor ileum. In conclusion, morphology analysis of pig small intestinal mucosa suggests that replacement of fetal type vacuolated enterocytes is resumed within 21 days after birth.
- ItemIntestinal MMC-related electric fields and pancreatic juice control the adhesion of Gram-positive and Gram-negative bacteria to the gut epithelium - in vitro study(2008) Jankowska, Alicja; Wrzesiński, Michał; Laubitz, Daniel; Kazimierczak, Waldemar; Skrzypek, Henryk; Bardowski, Jacek; Zabielski, Romuald; Grzesiuk, ElżbietaThe adhesion of six different Lactobacillus and Lactococcus and three pathogenic Escherichia and Salmonella strains was studied using Caco-2 cell line. In this in vitro model system the influence of weak electric field (EF) on bacterial adhesion was tested. The EF source was the in vitro reconstruction of spiking potentials recorded in the duodenum of a healthy calf during one myoelectrical migration complex (MMC) cycle. The ability to adhere to Caco-2 cells of bacteria belonging to two groups, Gram-positive lactobacilli and lactococci, and Gram-negative Escherichia and Salmonella differed considerably. The pathogenic bacteria adhered better to well-differentiated Caco-2 cells whereas lactobacilli and lactococci displayed better adhesion to non-differentiated Caco-2 cells. In the presence of MMC-related EF an increased adhesion of Lactobacillus and Lactococcus but not of Salmonella enterica s. Enteritidis and E. coli 269 to Caco-2 cells was observed. Two later strains adhered even less in the presence of EF. The same tendency was found in the presence of pancreatic juice in a cell medium. In conclusion, the myoelectric component of the small intestinal motility, the MMC-related EF, and pancreatic juice may increase the ability of lactic acid bacteria to adhere to GI epithelial cells, creating better environmental conditions for colonization of the intestine and competition with Gram-negative pathogens.
- ItemRational design of novel ligands for environmentally benign cross-coupling reactions(Walter de Gruyter, 2011) Demchuk, Oleg M.; Kielar, Katarzyna; Pietrusiewicz, Kazimierz MichałTransition-metal (TM) complexes of new phosphines, readily prepared by a straight forward three-step modular synthesis, were successfully employed in difficult crosscoupling reactions conducted under mild conditions (water, “open-flask”, low temperature) that aspire to meet green chemistry criteria. High yielding catalyzed by bismuth or rhodium complexes oxidative arylation of naphthoquinone gave the key 2-arylnaphthoquinone intermediates for facile bismuth triflate-catalyzed Michael addition of secondary phosphine oxides. Subsequent O-methylation and reductions of the resulting products gave access to the target air-stable phosphine ligands in good overall yields (up to 60 %).
- ItemEfektywność porażania larw chrabąszcza majowego (Melolontha melolontha L.) przez entomopatogeniczne nicienie(Instytut Ochrony Roślin - Państwowy Instytut Badawczy, Polskie Towarzystwo Ochrony Roślin, 2011-06-15) Kreft, Anna; Skrzypek, Henryk; Kazimierczak, Waldemar; Lech-Pituch, Ewelina; Skrabucha, AnnaExperiments done and presented below aimed at proving that applied species and Polish strains of entomopathogenic nematodes (EPNs) can be used to reduce the number of Melolontha melolontha. Invasive larvae of Steinernema arenarium Bys, S. arenarium Lub, S. feltiae Rap, Heterorhabditis bacteriophora Sie, H. megidis Pla, H. megidis Lub i H. megidis Pla, H. megidis C3 were used in the experiments as biocontrol agents against the larvae L1, L2 and L3 of M. melolontha. The experiments were done at 20°C, in 25 ml boxes filled with pasteurized (3 h at 70°) and air-dried soil. Pathogen doses were 100 IJ/insect. The result showed that susceptibility of M. melolontha to EPNs depends on the insect's developmental stage. Larvae L1 were the most susceptible. S. arenarium Bys and H. megidis strains were more effective in infecting M. melolontha larvae than S. feltiae Rap and H. bacteriohora Sie.
- ItemCharakterystyka nicieni wyizolowanych z pędraków chrabąszcza Melolontha sp. (Coleoptera: Scarabaeidae)(Instytut Ochrony Roślin - Państwowy Instytut Badawczy, Polskie Towarzystwo Ochrony Roślin, 2012-06-15) Kreft, Anna; Kazimierczak, Waldemar; Sierpińska, Alicja; Skrzypek, Henryk; Skrabucha, Anna; Dybała, Magdalena; Dźwierzyńska, MonikaCelem badań była charakterystyka nicieni porażających pędraki chrabąszcza Melolontha sp. w warunkach naturalnych. Pędraki chrabąszcza były zebrane na terenie nadleśnictw Krasnystaw, Kozienice, Opoczno i Brzeziny, na powierzchniach różniących się warunkami świetlnymi, wilgotnościowymi i temperaturowymi. Identyfikację gatunków przeprowadzono metodą sekwencjonowania fragmentów DNA (deoxyribonucleic acid) oraz metodami morfologicznymi przy zastosowaniu skaningowego mikroskopu elektronowego i mikroskopu optycznego z kontrastem interferencyjno-różnicowym. Uzyskane wyniki wykazały, że pędraki były porażone przez Diplogasteroides magnus oraz Koerneria sp. i Rhabditis sp. Większość zainfekowanych przez nicienie pędraków została zebrana na powierzchniach zadrzewionych, czyli tam, gdzie powierzchnia gleby była dobrze ocieniona, a wilgotność najwyższa.
- ItemAddenum to the description of Steinernema jollieti Spiridonov, Krasomil-Osterfeld & Moens, 2004(The Russian Society of Nematologists, 2012-11-14) Skrzypek, Henryk; Kazimierczak, Waldemar; Kreft, Anna; Spiridonov, Sergei; Mráček, ZdeněkAdditonal morphological data are provided for Steinernema jollieti Spiridonov, KrasomilOsterfeld, Moens, 2004. A light and scanning electron microscopy were used to particularize taxonomically important characters missing in the first decsription. The GS% and SW% indices are provided for males. The distribution of genital papillae on male tail is illustrated with SEM images. Structure of female tail and vulvar area are decsribed for females of the first and second generation. The relationships of S. jollieti with other steinernematid feltiae/kraussei group species are discussed.
- ItemCholinesterase inhibitors isolated from bilberry fruit(Elsevier, 2014) Demchuk, Oleg M.; Borowiec, Kamila; Szwajgier, Dominik; Targoński, Zdzisław; Cybulska, Justyna; Czernecki, Tomasz; Malik, AgnieszkaCholinesterases (ChEs) are key enzymes in the pathogenesis of Alzheimer's disease (AD). A growing body of evidence suggests that plants deliver compounds able to inhibit ChEs (e.g., huperzine A, galanthamine, and physostigmine), thus playing a beneficial therapeutic role in the treatment of AD. Screening for cholinesterase inhibitors (ChEIs) in selected fruits and vegetables showed that extract prepared from bilberry fruit effectively inhibited the activity of acetyl- and butyrylcholinesterase. The purification of ChEIs from bilberry fruit followed by HPLC-UV, FT-IR, NMR, and LC–MS demonstrated that the studied compounds were derivatives of chlorogenic and benzoic acids. These results confirm that bilberry fruit may serve as a useful source of ChEIs, leading to the attenuation of memory deficit caused by AD.
- ItemRegio- and stereoselectivity of polar [2+3] cycloaddition reactions between (Z)-C-(3,4,5-trimethoxyphenyl)-N-methylnitrone and selected (E)-2-substituted nitroethenes(Versita, 2014) Demchuk, Oleg M.; Jasiński, Radomir; Ziółkowska, Magda; Maziarka, Agata[2+3] Cycloaddition reactions of the highly reactive (Z)-C-(3,4,5-trimethoxyphenyl)-N-methylnitrone with (E)-2-R-nitroethenes proceed under mild conditions and yield mixtures of stereoisomeric 2-methyl-3-(3,4,5-trimethoxyphenyl)-4-nitro-5-R-isoxazolidines. The effect of regiospecificity of the cycloadditions may be accounted for by the theory of electrophilicity indexes. Stereoselectivity, however, is determined by a compilation of steric and secondary orbital effects.
- ItemNew Insights into the Mechanism of Reduction of Tertiary Phosphine Oxides by Means of Phenylsilane(Wiley-Blackwell, 2015) Demchuk, Oleg M.; Jasiński, Radomir; Pietrusiewicz, Kazimierz MichałThe mechanism of the reduction of phosphine oxides by PhSiH3 was established on the basis of kinetic measurements and Density Functional Theory (DFT) calculations. In particular, it has been proved that the model reaction between tri-n-butylphosphine oxide and phenylsilane occurs via a nonpolar mechanism. The data presented herein allow prediction and verification of the applicability of the new reduction reagents and conditions for industrially attractive processes.
- ItemA Quantum-Chemical DFT Approach to Elucidation of the Chirality Transfer Mechanism of the Enantioselective Suzuki–Miyaura Cross-Coupling Reaction(Hindawi, 2017) Demchuk, Oleg M.; Jasiński, Radomir; Babyuk, DmytroThe DFT calculations of the simplified model of the asymmetric Suzuki–Miyaura coupling reaction were performed at the M062x/LANL2DZ theory level at first. It was found that enantioselective reactions mediated by the palladium complexes of chiral C,P-ligands follow a four-stage mechanism similar to that proposed previously as one of the most credible mechanisms. It should be underlined that the presence of substituents in the substrates and the chiral ligand at ortho positions determines the energies of possible diastereoisomeric transition states and intermediates in initial reaction steps. This suggests that, in practice, a sharp selection of theoretically possible paths of chirality transfer from the catalyst to the product should have a place and, therefore, the absolute configuration of the formed atropisomeric product is defined and can be predicted.
- ItemA clean and simple method for deprotection of phosphines from borane complexes(Walter de Gruyter, 2017) Demchuk, Oleg M.; Jasiński, Radomir; Strzelecka, Dorota; Dziuba, Kamil; Kula, Karolina; Chrzanowski, Jacek; Krasowska, DorotaSimple, efficient, clean, and stereospecific protocols of protection of phosphorus atom with borane and deprotection from the borane complexes of the tertiary phosphines in mild conditions are reported. The proposed protection/deprotection reactions tolerate a range of functional groups and lead to pure products with excellent yield with no need for application of chromatographic or crystallisation purification procedures. For the first time mechanisms of the reactions of phosphine protection and deprotection have been studied based on experimental kinetic data as well as quantumchemical calculations, which allows designing reaction conditions suitable for a given substrate.
- ItemGreen in water sonochemical synthesis of tetrazolopyrimidine derivatives by a novel core-shell magnetic nanostructure catalyst(Elsevier, 2018) Demchuk, Oleg M.; Maleki, Ali; Rahimi, Jamal; Wilczewska, Agnieszka Z.; Jasiński, RadomirA green approach for the one-pot four-component sonochemical synthesis of 5-methyl-7-aryl-4,7-dihydrotetrazolo[1,5-a]pyrimidine-6-carboxylic esters from the reaction of 2-cyano-guanidine, sodium azide, various aromatic aldehydes and methyl or ethyl acetoacetate in the presence of a catalytic amount of Fe2O3@SiO2-(CH2)3NHC(O)(CH2)2PPh2 as a new hybrid organic–inorganic core–shell nanomagnetic catalyst is described. This is the first design, preparation, characterization and application of the present nanomaterial and also the first ultrasound irradiated synthesis of the biologically and pharmaceutically important heterocyclic compounds in water as a green solvent. This novel sonocatalysis/nanocatalysis protocol offers several advantages such as high yields, short reaction times, environmentally-friendly reaction media, easily isolation of the products, simple preparation, full characterization and recoverability of the nanocatalyst by an external magnet and reusing several times without significant loss of activity.
- ItemA representative of arylcyanomethylenequinone oximes effectively inhibits growth and formation of hyphae in Candida albicans and influences the activity of protein kinases in vitro(Elsevier, 2018) Masłyk, Maciej; Janeczko, Monika; Demchuk, Oleg M.; Boguszewska-Czubara, Anna; Golczyk, Hieronim; Sierosławska, Anna; Rymuszka, Anna; Martyna, Aleksandra; Kubiński, KonradIn this study, we applied various assays to reveal new activities of phenylcyanomethylenequinone oxime-4-(hydroxyimino) cyclohexa-2,5-dien-1-ylidene](phenyl)ethanenitrile (4-AN) for potential anti-microbial applications. These assays demonstrated (a) the antimicrobial effect on bacterial and fungal cultures, (b) the effect on the in vitro activity of the kinase CK2, (c) toxicity towards human erythrocytes, the Caco-2 cancer cell line, and embryonic development of Zebrafish. We demonstrated the activity of 4-AN against selected bacteria and Candida spp. The MIC ranging from 4 µg/ml to 125 µg/ml proved effective in inhibition of formation of hyphae and cell aggregation in Candida, which was demonstrated at the cytological level. Noteworthy, 4-AN was found to inhibit the CK2 kinase with moderate potency. Moreover, at low concentrations, it did not exert any evident toxic effects on human erythrocytes, Caco-2 cells, or Zebrafish embryos. 4-AN can be a potential candidate as a novel drug against Candida infections.
- ItemRegiospecific formation of the nitromethyl-substituted 3-phenyl-4,5-dihydroisoxazole via [3 + 2] cycloaddition(Springer Nature, 2018) Demchuk, Oleg M.; Mirosław, Barbara; Babyuk, Dmytro; Łapczuk-Krygier, Agnieszka; Kącka-Zych, Agnieszka; Jasiński, Radomir5-(Nitromethyl)-3-phenyl-4,5-dihydroisoxazole was obtained as a product of a high-yielding [3 + 2] cycloaddition reaction of in situ-generated benzonitrile N-oxide and 3-nitroprop-1-ene. For the first time, the regiochemistry of this reaction was unambiguously proven by X-ray structural analysis. The quantum-chemical calculation performed at the M06-2X/6-31G(d) (PCM) theoretical level affords a basis for explaining the course of reaction as well as the nature of transition states. Next, further DFT calculations together with spectral data shed light on structural aspects of the product.
- ItemMechanisms involved in the development of the small intestine mucosal layer in postnatal piglets(Kraków: Polish Physiological Society, 2018) Skrzypek, Tomasz; Kazimierczak, Waldemar; Skrzypek, Henryk; Valverde Piedra, Jose Luis; Godlewski, Michał; Zabielski, RomualdThe use of complementary visualization and measurement techniques allowed accurate description and quantification of changes in the intestinal mucosal architecture and provided a comprehensive outlook on the dynamics of remodeling and maturation processes of the mucosal layer taking place in the small intestine of piglets from birth to weaning. The aim of the study was to examine the early postnatal development of the small intestine in pigs. Three techniques were used: scanning electron microscopy (measurements ofvillus density and shape, height ofenterocytes and microvilli, cell exfoliation, and location of extrusion zones), optical microscopy (cross section, measurement of structures: villus length and width; crypt depth; mucosal thickness), and confocal microscopy (cell localization, apoptosis, exfoliation and migration). The postnatal development ofthe mucosal layer ofthe small intestine was reflected in changes in the density, length, width, and shape of villi, crypt depth, replacement of enterocyte population, and arrangement. The presence of deep transverse furrows on villus corpus and vacuolated fetal-type enterocytes in the mucosal layer of the small intestine, which are able to engulf large amounts of colostrum shortly after birth, appears to play an important role in the observed phenomenon of straightening of the villus height and increasing of the villus diameter shortly after birth. We hypothesized that the intestinal mucosal layer is compressed before birth and ready to unfold within a short time after birth.
- ItemFunctional traits of Lactobacillus plantarum from fermented Brassica oleracea var. capitata L. in view of multivariate statistical analysis(Springer, 2018-05-04) Polak-Berecka, Magdalena; Kubik-Komar, Agnieszka; Gustaw, Klaudia; Michalak, Magdalena; Kazimierczak, Waldemar; Waśko, AdamIn the present study, Lactobacillus plantarum strain was isolated and identifid from spontaneous fermentation of Brassica oleracea var. capitata L. We used the Unweighted Pair Group Method with Arithmetic Mean Analysis (UPGMA) and Principal Component Analysis (PCA) to examine the variations in the functional properties of the isolates. Six functional traits were analyzed, i.e., viability at low pH, resistance to lysozyme and to SIF, auto- and coaggregation, and ß-glucosidase activity. The present work is the fist study in which the PCA and UPGMA statistical methods were used together to analyze data obtained from the same microbiological experiments. This provided information about the similarity of the examined isolates in terms of their functional traits. Additionally, the level of the analyzed functional traits within the particular groups of isolates was shown. The presented approach is the basis for choosing isolates that are most closely related to the reference strain isolated from pickled cabbage.
- ItemSteinernema poinari (Nematoda: Steinernematidae): a new symbiotic host of entomopathogenic bacteria Xenorhabdus bovienii(Springer, 2018-06-19) Sajnaga, Ewa; Kazimierczak, Waldemar; Skowronek, Marcin; Lis, Magdalena; Skrzypek, Tomasz; Waśko, AdamThree strains of symbiotic bacteria were isolated from an entomopathogenic nematode Steinernema poinari retrieved from soil in eastern Poland. Using 16S rDNA, recA, gltX, gyrB, and dnaN gene sequences for phylogenetic analysis, these strains were shown to belong to the species Xenorhabdus bovienii. The nucleotide identity between the studied S. poinari microsymbionts and other X. bovienii strains calculated for 16S rDNA and concatenated sequences of four protein-coding genes was 98.7–100% and 97.9–99.5%, respectively. The phenotypic properties of the isolates also supported their close phylogenetic relationship with X. bovienii. All three tested X. bovienii strains of diffrent Steinernema clade origin supported the recovery of infective juveniles and subsequent development of the nematode population. However, the colonization degree of new infective juvenile generations was signifiantly affcted by the bacterial host donor/recipient. The colonization degree of infective juveniles reared on bacterial symbionts deriving from a non-cognate clade of nematodes was extremely low, but proved the possible host-switching between non-related Steinernema species.
- ItemThe contribution of vacuolated foetal-type enterocytes in the process of maturation of the small intestine in piglets(Kielanowski Institute of Animal Physiology and Nutrition, 2018-08-27) Skrzypek, Tomasz; Szymańczyk, Sylwia; Ferenc, Karolina; Kazimierczak, Waldemar; Szczepaniak, Klaudiusz; Zabielski, RomualdIn neonates the vacuolated foetal-type enterocytes (VFE) play a key role in the transport of intact colostral and milk proteins from the lumen of the small intestine into the circulation and/or in the intracellular digestion of intestinal nutrients. The absorption of intact colostral macromolecules (including immunoglobulins, hormones and bioactive peptides) is important in the development of the immune and digestive systems of newborn piglets. The digestion of the intestinal content inside the VFE supports the luminal digestion of nutrients. The presence of apical canalicular system, which produces both the transport and the digestive vacuoles, is a key feature of VFE. The VFEs are gradually replaced by adult-type enterocytes. VFEs disappear gradually from the proximal part of the small intestine to the ileum. VFEs containing large (also referred to as giant) transport vacuoles disappear within the first 2–3 days after birth. VFEs containing digestive vacuoles are present for up to week 3 of life. In contrast, VFEs of intrauterine growth retarded piglets show abnormalities in their development of the apical area. The loss of VFEs is a good marker of the small intestine epithelium maturation.